   (defmethod scalar-schema-generator :enum [_]
     (tc.gen/fmap (fn [enum-values]
                    [:enum {} enum-values])
-                 (tc.gen/not-empty (tc.gen/set tc.gen/keyword))))
+                 (tc.gen/not-empty (tc.gen/set simple-keyword-generator))))
 
   (defmulti compound-schema-generator
     (fn [schema-name inner-generator] schema-name)

  (defmethod compound-schema-generator :record [_ inner-generator]
    (tc.gen/fmap (fn [schemas]
                   [:record {} schemas])
                 (tc.gen/map tc.gen/keyword inner-generator)))

  (defmethod compound-schema-generator :tuple [_ inner-generator]
    (tc.gen/fmap (fn [schemas]

           (map scalar-schema-generator)
           (tc.gen/one-of))))

  (def ^:const scalar-schema-size 1)
  (def ^:const max-schema-size 1000)
  (def ^:const coll-schema-size-multiplier 30)

  (defmulti schema-size
    compiler.schema/schema-name
    :hierarchy #'compiler.schema/extended-hierarchy)

  (defmethod schema-size :scalar [_]
    scalar-schema-size)

  (defmethod schema-size :optional [[_ _ schema']]
    (schema-size schema'))

  (defmethod schema-size :wrapped [[_ _ _ _ schema']]
    (schema-size schema'))

  (defmethod schema-size :multi [[_ _ _ schema']]
    (schema-size schema'))

  (defmethod schema-size :coll [[_ _ schema']]
    (* coll-schema-size-multiplier (schema-size schema')))

  (defmethod schema-size :map [[_ _ key-schema' value-schema']]
    (* coll-schema-size-multiplier (+ (schema-size key-schema')
                                      (schema-size value-schema'))))

  (defmethod schema-size :record [[_ _ schemas']]
    (->> schemas'
         (vals)
         (map schema-size)
         (reduce +)))

  (defmethod schema-size :tuple [[_ _ schemas']]
    (->> schemas'
         (map schema-size)
         (reduce +)))

  (def schema-generator
    (tc.gen/such-that (fn [schema]
                        (< (schema-size schema) max-schema-size))
                      schema-generator*))

  (defmulti value-generator
    compiler.schema/schema-name
